Artist&#39;s knife



CL 20, 1959 NlTENsQN l 2,908,972

ARTIST'S KNIFEl Filed July 51, 1956 IIIIIII III United States Patent C)2,908,972 p Y Aurrsrs KNrFE -Edward Nitenson, Sharon, Mass. v i"Application July 31, 1956, Serial No. 601,208 i 6 claims. (cl. sti-293) v' Ihis invention relates to cutting tools and more particularlycomprises a new and improved precision cutting tool .of the type used byartists and draftsmen.

One mportantobject of my invention is to provide a cutting tool having ablade which may be set at any desired distance beneath the bottom of theframe which holds it.

Another important object of my invention is to provide a regulator oradjustment for the blade which may easily be operated manually.

Still another important object of my invention is to provide a cuttinginstrument which may easily be guided along a straight edge.

Yet another important object of my invention is to provide a cuttingtool which may be used with equal ease by both left-handed andright-handed persons To accomplish these and other objects of myinvention my precision cutting tool includes, among its severalfeatures, a frame having a vertical slotted region extending across itsbottom and terminating short of the top of the'frame. Extending acrossthe frame and through the slotted region are drilled'holes adapted toreceive a pin which pivotally supports the cutting blade. The cuttingblade which may be a standard Exacto blade may be selectively pivoted ateither of the holes.

Two additional holes are drilled vertically in the frame with their axescoincident with the center of the slotted region. A spring is disposedin the bottom of one of the additional holes and bears against the loweror cutting edge of the blade, while a screw having a knurled head isthreaded into the top of -that hole and bears against the top edge ofthe blade. By tightening the screw in the hole, the blade is loweredagainst the bias of the spring so that it extends a greater distance outof the slotted region and below the bottom of the frame. The screwitself provides a firm bearing surface for the blade when the instrumentis in use and prevents the blade from re? `ice y description of twoembodiments thereof, selected for tracting into the slotted region oftheframe when pres# sure is applied-against its cutting edge.

The blade, the pin, the spring and the screw may be reversed in theframe, for duplicate holes are provided for this purpose.' This featurepermits the blade to be drawn across a straight edge from either left toright or right to left, so that the tool may easily be handled b eithera right-handed or left-handed person. i

In addition to the features alluded to above, the frame of my cuttingtool includes a ange which cooperates with the-side of the frame to forma guide so that the tool may be drawn along a straight edge. The sideedges of the frame beneath the flange are rounded so that when the toolis drawn along the straight edge, it will run smoothly and Snot gougethe straight edge. Because this guide lies on but one side of the frame,it is, of course, of great advantage to have the flexibility of bladeposition as described in the preceding paragraph. x

Asp another feature of my invention, the precision cutpurposes ofillustration and` shown in the accompanying drawing wherein:

Figure l is a frontv elevation view of a precision cutter constructed inaccordance with my invention', pp

Figure 2 is a cross-sectional View taken alongthe corresponding sectionlines of Figure 3, v

Figures 3 and 4 are cross-sectional viewstaken along the correspondingsection lines of Figure 2,

Figure 5 is a partial cross-sectional view taken alongV thecorresponding section lines of Figure 1, and,

Figure 6 is a View similar to that of Figure 2 and illustrating aslightly modiled frame. .t The embodiment of my invention illustrated inFigures l-5 includes a frame 10 having a vertical slot 12 extendingacross its entire width and a cutting blade 14. y

The frame 10 is rectangular in cross section (see Figure 2) and has apair of parallel legs 16 which define the sides of the slot12. A pair ofparallel holes or openings lfextendthrough the legs 16 and normal totheslot 1,2, one end of each of the holes being counter-sunk; while theirother ends are threaded. Either of the holes may receive a screw 20Vwhich extends across the slot v12 and through the opening 22 formedinthe blade 14.

From the foregoing description, it will be Vapparent that the blade 14may be mounted either inthe position shown in Figure 2er alternativelyon the opposite side of the frame 10 by threading the screw 20 into theother hole 18 provided in the frame. The reasons for this will be morefully explained in the following paragraphs.

A pair of recesses 24 and 26 are formed vertically in the frame 10, oneon the outside of each of the holes 18. The axes of the recesses 24and'26 are coincident with the` center of the slot 12. This feature isclearly`shown in- Figure 4. The recesses 24 and 26 areA somewljatrwiderkthan the width; of the slot 12 and thus are capable 'of supporting aspring 28 at their bottoms.'v The spring 28,' shown at the bottom ofrecess 24 in Figures 2 and 4, bears against the lower cutting edge 30 ofthe blade 14 and. urges the blade upwardly in the s1otf12 in aclockwise. direction aboutthepivotal support pin 20. A screwfv32v havinga knurled head 34 is threaded into the recess 24.` and its lower endabuts against the'upper edge 36 ofthe blade 14. The recess 24 is, ofcourse, threaded to receive the screw 32, these threads extendingdownwardly from the top of the frame 10 to the slot`r12. These threadsmay, of course, extend downwardly to Vthe bottom of the recess; but thisis unnecessary. From the foregoing description, it will be appreciatedthat by tightening the screw 32 into the frame 10, the blade 14 isforced downwardly by the bottom of the screw` against the bias of thespring 28 so that it assumes a lower position in the slot 12; that is,the blade assumes a greaterV angle with the horizontal, thus moving itsend 38 a greater distance belorwlthe bottom of the frame.` In thismanner, the screw 32 provides a precision adjustment for the blade 14 sothat the exact depth of the cut made by the blade may beselected-readily. It will be noted also that the bottom of the screwV 32which bears against the upper edge 36 of the blade 14 provides a solidbearing surface for the blade and will not permit it to move upwardlylwhen pressure is applied `to the cutting edge 30 as the Vtool is used.The spring 28 constantly urges the blade against the bottom of the screwand assures the operatorthat then blade is 'positioned at the depthselected. The

" lcnurled head 34 of the screw affords the user'a ready Y 3 means ofquickly adjusting the cutting depth of the blade without the need ofadditional tools.

A ange 40 carried on the side of the frame 10 cooperates with the sidewall 42 of the frame to form a lguide for drawing the instrument along astraight edge. When a cut is to be made with the aid of a triangle, Tsquare, or other straight-edged instrument, the flange 40 rides on theupper surface of that instrument while the side wall 42 rides along theedge of the instrument to guide the tool along a straight line. Theiiange 40 actually controls the depth of the cut made by the knife orblade 14, while the surface 42 of the side of the frame vguides the toolalong a straight line.

It will be noted in Figure 5 that the edges 44 of the side wall 42 arerounded. The rounded edges prevent gouging of the straight edge when thetool is drawn along it. The radius of the edges 44, of course, must berather small so as not to introduce any tendency for the tool to rock onthe edge.

The importance of being able to mount the blade either in the positionshown in Figure 2 or alternatively in the reverse position with theblade extending tothe lower right corner of the frame may now be fullyappreciated. It is natural for a right-handed person to draw a tool ofthis kind from left to right across the straight edge of a square,triangle or other similar guide. However, it is extremely awkward for aleft-handed person to do this. With the blade mounted as shown in Figure2, a right-handed person may use the instrument naturally; that is, hecan draw the blade across the straight edge from left to right. Aleft-handed person who naturally draws an instrument of this kind fromright to left would ind it desirable to shift the position of the blade14 so that it extends downwardly and to the right as viewed in Figure 2.The second hole 18 and the recess 26 are provided so that this changemay be made quickly and without diiiiculty. To accomplish this reversalof parts, the pin 20, the spring 28, the screw 32 and the blade 14 arefirst removed from the frame. Then the user merely drops the spring 28into the recess 26 from the top of the frame 10, next slides the end ofthe blade 14 into the slot 12, which will be turned over from theposition shown in Figure 2, and aligns the hole 22 in the blade with thesecond hole or opening 18. Next, the screw is threaded into the hole 18,and the screw 32 is turned into the recess 26. By this very simpleoperation, the blade is positioned for comfortable use by a left-handedperson. The cutting edge 30 of the blade 14 will face downwardly and ina position to be drawn from right to left across a straight edge.

As shown, the end 38 of the blade 14 extends beyond lthe end ofthe frame10. This is true whether the blade is mounted in the positionillustrated or in the reverse positionpsuitable for left-handed users.This allows the end of the blade '58 to be seen by the user and thuspermits him to align the blade with a prescribed cutting line. If

, 4 4 the pivotal action of the blade. Of course, other means could beused to accomplish the same purpose.

The instrument that I have invented is very easy to use and is wellbalanced so that it will easily ride along a straight edge withoutwobbling or tilting. The major portion of the Weight of the instrumentlies on the side of the blade nearer to the flange 40. Thus, the centerof gravity of the instrument will be disposed above the surface of thestraight-edge instrument; and it will have no tendency to tilt outwardlyaway from the straight edge. As a result, the blade 14 will maintain itsvertical alignment, and a square edge will be provided the materialwhich is eut by it. Because it is desirable to have the instrumentcentered in this fashion, the guide for moving the instrument along astraight edge is confined to but one side of the frame 10. This, ofcourse, ycreates the need for providing means for shifting the positionof the blade 14 to suit both left-handed and right-handed users.

In view of the fact that numerous modifications may be made of myinvention, I do not intend to limit its scope to the specific embodimentillustrated and described; rather it is my intention that the breadth bedetermined by the `appended claims and their equivalents.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A device of the character described comprising an elongated frame,said frame having means defining an upwardly extending slotted regionlongitudinally in the bottom of the frame and elongated so that theslotted region extends to the ends of the frame, a pair of spaced apaitdownwardly extending threaded recesses formed in the top of the frameintermediate its ends and intersecting the slotted region, each of therecesses being wider than said slotted region and having their centerscoincident with the center of the slotted region, a pair of spaced aparthorizontal openings formed in the frame between the recesses andintersecting the slotted region, one of said openings being adjacent onerecess and the other of said openings being adjacent the other recess,an elongated single edge cutting blade having 'an opening adjacent oneend, a pin adapted to iit into either of the openings in the frame andthrough the opening in the blade and selectively support the blade inthe slotted region so that it extends out either end of the slottedregion and with the cutting edge facing downwardly, said blade passingthrough the recess adjacent the opening into which the pin is itted, aspring disposed in the bottom of that recess below the blade and bearingupwardly against the bottom of the blade biasing -the blade upwardly inthe slotted region, and a screw disposed in that recess and extendingdownwardly to the top of the blade for moving the l blade downwardlyagainst the bias of the spring.

the blade were completely hidden by the frame, it would be impossiblefor an operator to View the exact location of the blade and thus itwould be extremely difficult for him to determine whether or not theblade was aligned with the line along which the cut was to be made.

The frame of the tool just described may be made of steel, or -otherrigid metal. However, it is not beyond the scope. of my invention to usenon-metallic material, such as plastic for it. Clearly the simple shapeof the frame makes it peculiarly susceptible to molding. If a plasticmaterial is used, it may prove necessary or desirable to add strengthand rigidity to the frame. In Figure 6, a tool frame 50 has a slot 54extending across its length as in the previous embodiment. However, thevslot is interrupted by a rib 52 which extends -between the sides of theslot 54. The `rib 52 prevents the legs forming the sides ofthe slot fromspreading, but does not interfere with 2. A device as defined in claim lfurther characterized by a rib disposed in the slotted region betweenthe openings and secured to the frame for strengthening the frame.

3. A device comprising a frame, a horizontal flange formed on one sideof the frame and above the bottom of the frame forming a guide to drawvthe frame along a straight edge, a pair of upwardly extending slotsformed in the bottom of the frame and parallel to said one side of theframe, a pair of spaced apart and downwardly extending recesses formedin the frame and one .intersecting each slot, a rib disposed between theslots and between the recesses and secured to the framefor strengtheningthe frame, a single edge cutting blade having an opening at one end, apin extending through the opening in the blade and adapted to be securedto the frame between the recess 'in either slot and the rib forselectively pivotally mounting the blade in that slot so that it extendsthrough one of they recesses with the cutting edge facing dovmwardly andwith the other end of the blade extending out of that slot, a springsecured to the frame and engaging the blade urging the blade to pivotupwardly in that slot, and a screw threaded downwardly into the recessthrough which the blade extends for limiting the upward pivotal movementof the blade under the influence of the spring.

4. A device of the character described, comprising an elongated frame, apair of aligned upwardly extending slots formed longitudinally in thebottom of the frame and elongated so that opposite ends of the Slotsextend to the ends of the frame, a pair of spaced apart downwardlyextending threaded recesses formed in the top of the frame intermediateits ends and one intersecting each of the slots, each of the recessesbeing wider than the slots and having their centers coincident with the`center of the slots, an elongated single edge cutting blade having anopening adjacent one end, a pin extending through the opening in theblade and adapted to be secured to the sides of either slot adjacent therecess intersecting that slot for selectively supporting the blade inthe slots so that it extends out either end of the frame with thecutting edge of the blade facing downwardly, said blade passing throughone of the recesses, a spring disposed in the bottom of said recessbelow the blade and bearing upwardly against the bottom of the bladebiasing the blade upwardly in that slot, and a screw disposed in thatrecess and extending downwardly to the top` of the blade for `moving theblade downwardly against the bias of the spring.

5. A device as defined in claim 4, further characterized by a horizontalange formed on one side of the frame and spaced upwardly from the bottomof the frame and forming with the lower portion of that side of theframe, a g-uide for drawing the frame along a straight edge.

6. A device comprising a frame, a horizontal ange formed on one side ofthe frame and above the bottom of the frame forming a guide to draw theframe along a straight edge, said frame having means dening an upwardlyextending slotted region in the bottom of the frame and parallel to saidone side of the frame, a pair of spaced apart and downwardly extendingrecesses formed in the frame and intersecting the slotted region, asingle edge cutting blade having an opening at one end, a pin extendingthrough the opening in the blade and adapted to be secured to the framebetween the recesses for selectively pivotally mounting the blade sothat it extends through either one of the recesses with the cutting edgefacing downwardly and with the other end of the blade extending out ofthe slotted region, a spring secured to the frame and engaging the bladeurging the blade to pivot upwardly in the slotted region, and `a screwthreaded downwardly into the recess through which the blade extends forlimiting the upward pivotal movement of the blade under the influence ofthe spring.

References Cited in the tile of this patent UNITED STATES PATENTS262,218 Geiger Aug. 8, 1882 1,475,264 Gundlaeh NOV. 27, 1923 1,737,552Altman et al. Dec. 3, 1929 2,282,062 Jewett May 5, 1942 V2,685,764vInl-Ipateld Aug. 10, 1,954

